Add EquatableArray<T> type

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/CommunityToolkit.Mvvm.SourceGenerators.projitems

@@ -69,6 +69,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\SyntaxNodeExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\TypeDeclarationSyntaxExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\Comparer{T,TSelf}.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Helpers\EquatableArray.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\HashCode.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\ImmutableArrayBuilder{T}.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\ObjectPool{T}.cs" />

CommunityToolkit.Mvvm.SourceGenerators/Helpers/EquatableArray.cs

@@ -0,0 +1,122 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
+using System.Linq;
+using System.Runtime.CompilerServices;
+
+namespace CommunityToolkit.Mvvm.SourceGenerators.Helpers;
+
+/// <summary>
+/// An imutable, equatable array. This is equivalent to <see cref="ImmutableArray{T}"/> but with value equality support.
+/// </summary>
+/// <typeparam name="T">The type of values in the array.</typeparam>
+internal readonly struct EquatableArray<T> : IEquatable<EquatableArray<T>>
+    where T : IEquatable<T>
+{
+    /// <summary>
+    /// The underlying <typeparamref name="T"/> array.
+    /// </summary>
+    private readonly T[]? array;
+
+    /// <summary>
+    /// Creates a new <see cref="EquatableArray{T}"/> instance.
+    /// </summary>
+    /// <param name="array">The input <see cref="ImmutableArray{T}"/> to wrap.</param>
+    public EquatableArray(ImmutableArray<T> array)
+    {
+        this.array = Unsafe.As<ImmutableArray<T>, T[]?>(ref array);
+    }
+
+    /// <sinheritdoc/>
+    public bool Equals(EquatableArray<T> array)
+    {
+        return AsImmutableArray().SequenceEqual(array.AsImmutableArray());
+    }
+
+    /// <sinheritdoc/>
+    public override bool Equals([NotNullWhen(true)] object? obj)
+    {
+        return obj is EquatableArray<T> array && Equals(this, array);
+    }
+
+    /// <sinheritdoc/>
+    public override int GetHashCode()
+    {
+        if (this.array is not T[] array)
+        {
+            return 0;
+        }
+
+        HashCode hashCode = default;
+
+        foreach (T item in array)
+        {
+            hashCode.Add(item);
+        }
+
+        return hashCode.ToHashCode();
+    }
+
+    /// <summary>
+    /// Gets an <see cref="ImmutableArray{T}"/> instance from the current <see cref="EquatableArray{T}"/>.
+    /// </summary>
+    /// <returns>The <see cref="ImmutableArray{T}"/> from the current <see cref="EquatableArray{T}"/>.</returns>
+    public ImmutableArray<T> AsImmutableArray()
+    {
+        return Unsafe.As<T[]?, ImmutableArray<T>>(ref Unsafe.AsRef(in this.array));
+    }
+
+    /// <summary>
+    /// Creates an <see cref="EquatableArray{T}"/> instance from a given <see cref="ImmutableArray{T}"/>.
+    /// </summary>
+    /// <param name="array">The input <see cref="ImmutableArray{T}"/> instance.</param>
+    /// <returns>An <see cref="EquatableArray{T}"/> instance from a given <see cref="ImmutableArray{T}"/>.</returns>
+    public static EquatableArray<T> FromImmutableArray(ImmutableArray<T> array)
+    {
+        return new(array);
+    }
+
+    /// <summary>
+    /// Implicitly converts an <see cref="ImmutableArray{T}"/> to <see cref="EquatableArray{T}"/>.
+    /// </summary>
+    /// <returns>An <see cref="EquatableArray{T}"/> instance from a given <see cref="ImmutableArray{T}"/>.</returns>
+    public static implicit operator EquatableArray<T>(ImmutableArray<T> array)
+    {
+        return FromImmutableArray(array);
+    }
+
+    /// <summary>
+    /// Implicitly converts an <see cref="EquatableArray{T}"/> to <see cref="ImmutableArray{T}"/>.
+    /// </summary>
+    /// <returns>An <see cref="ImmutableArray{T}"/> instance from a given <see cref="EquatableArray{T}"/>.</returns>
+    public static implicit operator ImmutableArray<T>(EquatableArray<T> array)
+    {
+        return array.AsImmutableArray();
+    }
+
+    /// <summary>
+    /// Checks whether two <see cref="EquatableArray{T}"/> values are the same.
+    /// </summary>
+    /// <param name="left">The first <see cref="EquatableArray{T}"/> value.</param>
+    /// <param name="right">The second <see cref="EquatableArray{T}"/> value.</param>
+    /// <returns>Whether <paramref name="left"/> and <paramref name="right"/> are equal.</returns>
+    public static bool operator ==(EquatableArray<T> left, EquatableArray<T> right)
+    {
+        return left.Equals(right);
+    }
+
+    /// <summary>
+    /// Checks whether two <see cref="EquatableArray{T}"/> values are not the same.
+    /// </summary>
+    /// <param name="left">The first <see cref="EquatableArray{T}"/> value.</param>
+    /// <param name="right">The second <see cref="EquatableArray{T}"/> value.</param>
+    /// <returns>Whether <paramref name="left"/> and <paramref name="right"/> are not equal.</returns>
+    public static bool operator !=(EquatableArray<T> left, EquatableArray<T> right)
+    {
+        return !left.Equals(right);
+    }
+}